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if a+b+c=15, a^2+b^2+c^2=83 find a^3+b^3+c^3-3abc. |
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Answer» (A + B + c)=15; squaring ( a^2+b^2+c^2+2(ab+bc+cs)=225; (83)+2(ab+bc+ca)=225; 2(ab+bc+ca)=225-83=142; (ab+bc+ca)=71; . a^3+ b^3+c^3-3abc=( a+b+c)(a^2+ b^2+c^2-( ab+bc+ca) =15(83-71)=15(12)=180; a^3+b^3+c^3-3abc=180 answer will be 180 perfect plz like my answer everyone |
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